Diatomaceous earth products, processes for preparing them, and methods of their use

Abstract

A particulate material includes agglomerated diatomaceous earth and a silicone binder. A process for preparing a diatomaceous earth product includes agglomerating at least one natural diatomaceous earth with at least one silicone material, and subjecting the agglomerated diatomaceous earth to at least one heat treatment at a temperature ranging from about 600° C. to about 1,000° C. A filter aid composition includes a diatomaceous earth product including an agglomerated diatomaceous earth and a silicone material. A method of filtering at least one liquid includes passing the at least one liquid through at least one filter membrane including a diatomaceous earth product including agglomerated diatomaceous earth and a silicone material.

1 - 47 . (canceled) 
     
     
         48 . A process for preparing a diatomaceous earth product, the process comprising:
 agglomerating at least one natural diatomaceous earth with at least one silicone material, and   subjecting the agglomerated diatomaceous earth to at least one heat treatment at a temperature ranging from about 600° C. to about 1,000° C.,   wherein the agglomerating comprises preparing at least one aqueous solution comprising the at least one silicone material, and contacting the at least one natural diatomaceous earth with the at least one aqueous solution.   
     
     
         49 . The process of  claim 48 , further comprising subjecting the at least one natural diatomaceous earth to at least one classification step prior to agglomerating. 
     
     
         50 . The process of  claim 48 , wherein the at least one aqueous solution comprises less than about 20% by weight water, relative to the weight of the diatomaceous earth. 
     
     
         51 . The process of  claim 50 , wherein the aqueous solution comprises less than or equal to about 10% by weight water, relative to the weight of the diatomaceous earth. 
     
     
         52 . (canceled) 
     
     
         53 . The process of  claim 48 , wherein the aqueous solution comprises about 1% to about 10% by weight of the at least one silicone material, relative to the weight of the diatomaceous earth. 
     
     
         54 . The process of  claim 53 , wherein the aqueous solution comprises about 1% to about 5% by weight of the at least one silicone material, relative to the weight of the diatomaceous earth. 
     
     
         55 . The process of  claim 48 , wherein the contacting comprises spraying the at least one aqueous solution onto the at least one natural diatomaceous earth. 
     
     
         56 . The process of  claim 48 , wherein the at least one silicone material comprises a silicone polymer comprising at least one of linear polymers, ring-shaped polymers, branched polymers, cross-linked polymers, and resins. 
     
     
         57 . The process of  claim 48 , wherein about 0.25 parts to about 1.5 parts of the at least one aqueous solution is contacted with about 1 part of the at least one natural diatomaceous earth. 
     
     
         58 . The process of  claim 57 , wherein about 1 part of the at least one aqueous solution is contacted with about 1 part of the at least one natural diatomaceous earth. 
     
     
         59 . The process of  claim 48 , wherein the diatomaceous earth product has a d 10  ranging from about 8.0 μm to about 15.0 μm. 
     
     
         60 . The process of  claim 48 , wherein the diatomaceous earth product has a d 50  ranging from about 20 μm to about 40 μm. 
     
     
         61 . The process of  claim 48 , wherein the diatomaceous earth product has a d 90  ranging from about 55 μm to about 120 μm. 
     
     
         62 . The process of  claim 48 , wherein the diatomaceous earth product has a permeability ranging from about 0.2 darcy to about 2.5 darcies. 
     
     
         63 . The process of  claim 48 , wherein the diatomaceous earth product has a quartz content less than about 1% by weight. 
     
     
         64 . The process of  claim 48 , wherein the diatomaceous earth product has a cristobalite content less than about 1% by weight. 
     
     
         65 . The process of  claim 48 , wherein the diatomaceous earth product has a pore volume ranging from about 3.5 mL/g to about 5.0 ml/g. 
     
     
         66 . The process of  claim 48 , wherein the diatomaceous earth product has a median pore diameter ranging from about 3.5 μm to about 5.0 μm. 
     
     
         67 . The process of  claim 48 , wherein the diatomaceous earth product has a wet density ranging from about 10 lb/ft 3  to about 25 lb/ft 3 . 
     
     
         68 . The process of  claim 48 , wherein the diatomaceous earth has a beer soluble iron content of less than about 40 ppm, as measured by ASBC.